5-Trihalogenomethyl-4,5-dihyro-oxazole-4-carboxylic acid esters
AssigneeTanabe Seiyaku Co., Ltd.
InventorsMunetsugu Miyoshi, Kazuo Matsumoto, Yuji Urabe, Tameo Iwasaki
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Abstract
Alkyl (or aralkyl) .alpha.-isocyanoacetate is condensed with a trihalogenoacetic aldehyde or its hydrate in the presence of an amine to give trans-4-alkoxycarbonyl(or aralkyloxycarbonyl)-5-trihalogenomethyl-2-oxazoline. The oxazoline compound is hydrolyzed under acidic conditions to give threo-.gamma.,.gamma.,.gamma.-trihalogenothreonine, which is then subjected to catalytic or electrolytic reduction. The above-mentioned reactions can be carried out stereoselectively and threo-threonine is thereby obtained without by-products such as allo-threonine.
Claims1
Trans-4-alkoxycarbonyl (or aralkyloxycarbonyl)-5-trihalogenomethyl-2-oxazoline of the formula:
- ##STR3## wherein R is methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, amyl, isoamyl, or benzyl, and X chlorine or bromine.
Dependencies are inferred from the claim text.